三种方法筛查孕妇B族链球菌的效果评价

目的 比较三种不同的方法检测B族链球菌的结果,对三种B族链球菌筛查方法进行效果评价.方法 收集我院2014年1月至2015年12月产科门诊孕35 ～ 37周孕妇1374例,采集孕妇的阴道拭子和肛周拭子标本,分别用血琼脂培养法,LIM肉汤增菌培养法和PCR方法检测B族链球菌.结果 1374例孕妇标本中,血琼脂培养法阳性60例,阳性检出率为4.4％,PCR方法检测阳性66例,阳性检出率为4.8％,LIM肉汤增菌培养法阳性128例,阳性检出率9.3％.三种筛查方法比较,LIM肉汤增菌培养法阳性率与PCR法,血琼脂培养法比较差异具有统计学意义.血琼脂培养法和PCR法筛查阳性率差异不具有统计学意义.以LIM肉汤增菌法为金标准,血琼脂培养法的灵敏度、特异性、阳性预测值、阴性预测值分别为46.9％,100％,100％,94.8％,PCR法的灵敏度、特异性、阳性预测值、阴性预测值分别为50％,99.6％,96.9％,95.1％.结论 LIM肉汤增菌培养法筛查B族链球菌的阳性率最高,血琼脂培养法和PCR法检测灵敏度较低,只能筛查出50％左右的GBS定植孕妇.建议临床筛查B族链球菌使用LIM肉汤增菌培养法筛查GBS,灵敏度高,特异性好.

Evaluation of Three Methods for Detection of Group B Streptococcus in Pregnant Women

Objective To evaluate methods of 5％ sheep blood agar culture,Polymerase chain reaction and LIM enrichment broth culture for detection of GBS in Pregnant women.Methods Vagino-rectal(VR) swabs were collected from 1374 women at 35 to 37 weeks of gestation.Culture on 5％ sheep blood agar,a selective Lim enrichment broth with subsequent culture on 5 ％ sheep blood agar and PCR assay were performed.The performance of 5 ％ sheep blood agar detection and PCR methods were compared with LIM enrichment broth culture.Statistical analysis was performed by Chi-Square test.Results LIM broth enrichment cultures were positive for 9.3％ of the specimen(128 out of 1374),Culture on 5％ sheep blood agar for 4.4％ (60 out of 1374),PCR assay for 4.8％ (66 out of 1374).Set LIM broth culture as a gold standard,the Sensitivity,Specificity,Positive predictive values and Negative predictive value of Culture on 5 ％ sheep blood agar were 46.9％,100％,100％,94.8％,and for that of PCR were 50％,99.6％,96.9％,95.1％,respectively.Conclusion LIM broth culture method is the test with high sensitivity and specificity for the detection of GBS colonizers during pregnancy.